Toroidal yoke for television cathode ray tube

ABSTRACT

A deflection yoke for a cathode ray tube comprises a hollow, substantially frusto-conical core having a plurality of coils toroidally wound thereabout. The coils have terminations to which connections will be made. A plurality of first projections are formed on the core and are circumferentially distributed thereabout between the ends of the core. A plurality of second projections are formed on the wide end of the core and are also circumferentially spaced thereabout. An annular terminal board for receiving the coil terminations is fitted over the narrow end of the core and is provided with slots for engaging the first projections. A protective housing having a shape roughly corresponding to the core is fitted over the terminal board and at its forward end is provided with slots which engage the second projections.

United States Patent [191 [111 3,783,424 Torsch Jan. 1, 1974 TOROIDALYOKE FOR TELEVISION CATHODE RAY TUBE [75] Inventor: Charles EdwardTorsch, Geneva,

[73] Assignee: GTE Sylvania Incorporated, Seneca Falls, NY.

[22] Filed: Nov. 16, 1972 121 1 Appl. No 307,027

[52] [1.8. CI. 335/210, 317/101 [51] Int. Cl H01! [58] Field of Search335/210; 313/75, 3l3/76;317/101 [56] References Cited UNITED STATESPATENTS 3,569,881 3/1971 Torsch 335/210 2,980,815 4/1961 Ecker 335/210 X3,390,363 6/1968 Weyrich et al. 335/210 3,629,750 12/1971 Nienaber335/210 3,307,128 2/1967 Kriadis 335/212 Primary Examiner-George HarrisAtt0rneyNorman J. OMalley et al.

[ 5 7 ABSTRACT A deflection yoke for a cathode ray tube comprises ahollow, substantially frusto-conical core having a plurality of coilstoroidally wound thereabout. The coils have terminations to whichconnections will be made. A plurality of first projections are formed ontho core and are circumferentially distributed thereabout between theends of the core. A plurality of second pro jections are formed on thewide end of the core and are also circumferentially spaced thereabout.An annular terminal board for receiving the coil terminations is fittedover the narrow end of the core and is provided with slots for engagingthe first projections. A protective housing having a shape roughlycorresponding to the core is fitted over the terminal board and at itsforward end is provided with slots which engage the second projections.

5 Claims, 3 Drawing Figures TOROIDAL YOKE FDR TELEVISION CATHODE RAYTUBE BACKGROUND OF THE INVENTION This invention relates to yokes forcathode ray tubes and more particularly to a toroidally wound yokeassembly for use on a cathode ray tube.

Toroidally wound deflection yokes for cathode ray tubes are known in theart. Such yokes comprise a frusto-conical core having a plurality oftoroidally wound coils thereabout. The terminations of the coils end ina terminal board which is affixed to the outside base of the yoke at thenarrow end thereof. Connecting wires leading to a plug are alsoconnected to the terminal board.

This arrangement of .the terminal board at the outside base of the corereducesthe amount of axial movement of the yoke along the neck of thetube and increases the difficulty of determining proper yoke position.This is particularly true since other components such as the convergenceassembly are also positioned on the neck of the tube.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of thisinvention to obviate the disadvantages of theprior art.

It is another object of the invention to reduce the overall length of atoroidally wound yoke without affecting its performance.

These objects are accomplished in one aspect of the invention by theprovision of a yoke having terminal board mounting means formedintermediate the ends of the yoke. An annular terminal board is affixedto the mounting means and does not extend beyond the base and thus doesnot add to the axial length of the yoke, Such a design allows muchgreater felxibility of yoke positioning than was possible heretofore.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explodedperspective viewof a yoke embodying the invention;

FIG. 2 is an elevational view of an assembled yoke minus the housing;and

FIG. 3 is an elevational view of the yoke with the housing in place.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding ofthe present invention, together with other and further objects,advantages and capabilities thereof, reference is made to the followingdisclosure and appended claims in conjunction with the above-describeddrawings.

Referring now to thedrawings with greater particularity, there is shownin FIG. 1 a disassembled yoke having a hollow, substantiallyfrusto-conica] core 12 of a magnetizable material. Core 12 has a wideforward portion or end 14 and a narrow base portion or end 16. The core12 is toroidally wound with a plurality of coils 18 (see FIGS. 2 and3)and is further provided with a plurality of first projections 20intermediate the ends 14 and 16. The projections 20 can be substantiallyequally circumferentially spaced thereabout or the spacing can beunequal in order to provide a keying arrangement. Additionally, theprojections 20 can be formed as part of a rear crown 22 of a suitableelectrically insulating material, as is shown in FIG. 1, or they can bebonded directly to core 12 ;by means of a suit- V able adhesive agent.

A plurality of second projections 24 are provided at the wide end 14 ofcore 12. These projections 24 likewise can be bonded directly to thecore 12 or can be formed as part of a forward crown 26. Secondprojections 24 are substantially equally circumferentially spacedthereabout.

An annular terminal board 28 is provided with a central aperture 30large enough to fit over the narrow end 16 of core 12 or rear crown 22.The inner wall 32 of aperture 30 is provided with a plurality of slots34, equal in number and spacing to first projections 20 and formed tomate therewith. The board 28 can be held in position on projections 20by cementing with a suitable agent or by melting the ends of firstprojections 20 and forming them over the board.

The terminations of coils 18 are affixed to terminal posts 36 on board28 .whereat other connections are made to provide leads 38 to a suitableplug 40 for connection to anappropriate source of power (see FIG. 2).

A protective housing 42 is also'provided, of substantiallyfrusto-conical configuration and of a size to completely encompass yoke10. The housing 42 comprises an annular forward section 44 and acup-like base section 46 the bottom 48 of which is provided with acentrally located aperture 50 at least large enough to pass over theneck 51 of a cathode ray tube52, shown in phantom in FIG. 3. The walls54 of base section 46 extend axially along core 12 at a distancesufficient to provide protection for terminal board 28. The forwardsection 44 and base section 46'are connected together by a plurality ofspaced ribs 56 whereby a series of windows is provided in housing 42.

Further, the forward section 44 is provided with mating means 58, inthis case a plurality of slots 60 for engagement with second projections24. Engagement in this instance is by a force fit which utilizes thenatural springiness of the housing material, which is preferably asuitable electrically insulating plastic. The plug 40 is passed throughone of the windows in the housing 42.

It will be seen that the novel yoke construction described above addsgreatly to the amount of adjusting movement of the yoke and provides anadvance in the art.

While there have been shown and described what are at present consideredto be the preferred embodiments of the invention, it will be apparent tothose skilled in the art that various changes and modifications can bemade therein without departing from the scope of the invention asdefined by the appended claims.

What is claimed is:

1. A deflection yoke for a cathode ray tube comprising: a hollow,substantially frusto-conical core; a plurality of coils toroidally woundabove said core having terminations; a plurality of first projectionsformed on said core intermediate the ends thereof; a plurality of secondprojections formed on the wide end of said core and substantiallycircumferentially spaced thereabout; a rigid, planar annular terminalboard for receiving said terminations fitted over said narrow end ofsaid core having slots therein engaging said first projections; and

a protective housing having a shape ro'ughly corresponding to said corefitting over said terminal board and having slots which engage saidsecond projections.

2. The yoke of claim 1 wherein said first and second projections areformed respectively on a rear crown said terminal board; said forwardsection and said base section being connected together by a plurality ofspaced ribs whereby a series of windows is provided in said housing.

4. The invention of claim 2 wherein said crowns are formed of anon-magnetic material.

5. The invention of claim 3 wherein said housing is formed of anon-magnetic material.

1. A deflection yoke for a cathode ray tube comprising: a hollow,substantially frusto-conical core; a plurality of coils toroidally woundabove said core having terminations; a plurality of first projectionsformed on said core intermediate the ends thereof; a plurality of secondprojections formed on the wide end of said core and substantiallycircumferentially spaced thereabout; a rigid, planar annular terminalboard for receiving said terminations fitted over said narrow end ofsaid core having slots therein engaging said first projections; and aprotective housing having a shape roughly corresponding to said corefitting over said terminal board and having slots which engage saidsecond projections.
 2. The yoke of claim 1 wherein said first and secondprojections are formed respectively on a rear crown and a forward crown,said crowns being respectively fixed to said narrow end of said core andsaid wide end of said core.
 3. The yoke of claim 1 wherein saidprotective housing comprises an annular forward section and a cup-likebase Section, the bottom of said base section being provided with acentrally located aperture at least large enough to pas over the neck ofsaid cathode ray tube, the walls of said base section extending axiallyalong said core a distance sufficient to provide protection for saidterminal board; said forward section and said base section beingconnected together by a plurality of spaced ribs whereby a series ofwindows is provided in said housing.
 4. The invention of claim 2 whereinsaid crowns are formed of a non-magnetic material.
 5. The invention ofclaim 3 wherein said housing is formed of a non-magnetic material.